The present invention relates generally systems for weighing and sorting food products, and more particularly to a high speed system for weighing static poultry parts and sorting the parts based on their weights.
Every year, the poultry industry processes millions of chickens for human consumption. Killed birds are commonly broken down into parts that are weighed, and sorted by weight. Consumers of poultry parts, such as fast food restaurant chains, purchase enormous quantities of poultry parts by number and weight. Processors are frequently required to supply a predetermined number of parts with the further requirement that each part must weigh at least a minimum amount. Payment is made on the basis of the number of parts delivered. In filling such an order, poultry parts must be weighed and sorted so that only parts that meet the weight criteria are delivered. To maximize efficiency, the weighing and sorting must be accomplished at high throughput rates. Moreover, the weighing process must be extremely accurate in order to assure that orders are properly filled without including parts that are materially heavier than the minimum weight requirement because, in effect, the additional weight of parts over the minimum weight is not reflected in the price paid. Small weight overages on individual poultry parts can adversely affect profit margins when thousands of parts are involved.
In order to assure the fastest possible processing speeds the prior art has proposed weighing techniques that rely on weighing parts as they are being conveyed to a sorting station. In some instances parts have been hung from conveyor elements that pass over load cells for determining weight. In other systems parts have been conveyed in individual carriers that move across weighing devices during transport. In still other systems, parts are deposited on a scale momentarily and then accelerated away. These systems have not been effective in yielding accurate weights at acceptably high weighing rates. The basic problem has been that when the poultry parts are moving, they may be unstable. That is, because the parts are not homogenous, elements of the parts may be shifting position relative to other elements while the part is being weighed. In prior art systems where the poultry parts have been allowed to come to rest before weighing, the weighing rates have been unacceptably low.
Prior art systems for sorting poultry parts have been constructed using conveyors that move weighed poultry parts along a path of travel past a series of receptacles lined up along one side of the conveyor. Sorting arms are pivoted along the conveyor side adjacent each receptacle so that the arm can be moved to extend at an angle across the conveyor from the receptacle. When a poultry part having the appropriate weight for accumulation in a given receptacle is moving down the conveyor, the arm associated with the given receptacle remains extended across the conveyor so the poultry part in question moves into contact with the arm and is guided into the receptacle. Other arms, associated with other receptacles are retracted so the poultry part may pass them by. These systems were effective to sort poultry parts but the conveyors that were required tended to be relatively lengthy if more than just a few weight ranges of poultry parts were being sorted. Thus these prior art sorters required appreciable floor space and the sorting process speed was reduced in relation to the increase conveyor length.
The present invention provides a new and improved system for weighing and sorting poultry parts that permits the parts to be statically weighed while maintaining high conveying speeds through the system, and wherein poultry parts can be sorted at high rates on conveyors that have minimum lengths.
The present invention provides a static weighing system for weighing and sorting poultry parts comprising a scale module for receiving poultry parts from an infeed conveyor and statically weighing them. The scale module comprises a plurality of scale units for weighing poultry parts received from the infeed conveyor, and a plurality of poultry part diverters for directing each poultry part received from the infeed conveyor to an individual scale unit. The scale units weigh the poultry parts after the poultry parts have come to rest and discharge the poultry parts to another conveyor so that the parts are statically weighed but the rate of poultry part movement through the system is not slowed by the weighing procedure.
According to another feature of the invention a sorter unit is provided that comprises an article conveyor for carrying articles along a travel path, first and second article receptacles respectively positioned on opposite sides of the travel path along a line that extends transverse to the path, at least first and second article sweeper elements for sweeping poultry parts off either side of the conveyor into one of the receptacles, a sweeper element carrier for moving the sweeper elements adjacent the article conveyor along the line and in a loop path, and a carrier drive unit for operating the carrier to shift either article sweeper element from one conveyor edge to the opposite conveyor edge along the line so that an article on the conveyor is swept into one of the article receptacles.
Other objects, features, and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the drawing and the appended claims.